Recent electronic devices have always been required to have a high efficiency and advanced functions and have also been desired to be miniaturized. Various kinds of technology have been developed for cellular phones and PHS (Personal Handyphone Systems) in particular.
For example, some cellular phones adopt a configuration in which an external shape changes between a standby mode and a use mode. In a case of what is called a clamshell type cellular phone, a receiver component having a display part and a microphone component having an operation part are opposed to each other and folded together in a standby mode. In a use mode, the receiver component and the microphone component are separated from each other so as to change into an elongated form. Furthermore, some cellular phones adopt what is called a slide type in which a receiver component and a microphone component are slidable. In the case of a slide type cellular phone, a receiver component and a microphone component are superimposed on each other in a standby mode. In a use mode, the receiver component and the microphone component are slid with respect to each other so as to change into an elongated form.
In either type of a clamshell type or a slide type, a flexible printed wiring board is generally used as a connection conductor (harness) for electrically connecting between internal circuit boards of a receiver component and a microphone component. Since a flexible printed wiring board has a structure in the form of a thin plate, it has excellent characteristics for reduction of a bend radius (the minimum bend radius is about 1 mm) and excellent resistance to repeated bending. Thus, a flexible printed wiring board is suitable to reduce the thickness of a product.
Particularly, if a clamshell type is selected, use of coaxial cables has been proposed to improve the transmission characteristics of signals and to avoid interference with other parts and influence from a disturbance (see Patent Document 1: JP-A 2006-333573).
Meanwhile, if a slide type is selected, circuit boards in a receiver component and a microphone component should be connected to each other with the receiver component and the microphone component being moved in a state in which a connection conductor is bent in a narrow clearance (see Patent Document 2: JP-A 2004-222173, Patent Document 3: International Publication WO2006-095382, and Patent Document 4: JP-A 2008-148248). Therefore, a flexible printed wiring board cannot entirely be replaced with coaxial cables.
Accordingly, there has been proposed that a shield is provided on a flexible printed wiring board that connects between circuit boards in a receiver component and a microphone component in order to avoid interference with other parts and influence from a disturbance when a slide type is selected (see Patent Document 5: JP-A 2008-131544).
Furthermore, use of the latest ultrafine coaxial cables has been proposed to connect between circuit boards in a receiver component and a microphone component when a slide type is selected (Patent Document 6: JP-A 2008-218389).